Prototypal Javascript

ES5 style

function Animal(name){
  this.name = name;
}

Animal.prototype.getName = function(){
  return this.name;
}

function Dog(name){
  Animal.call(this, name);
}

Dog.prototype = Object.create(Animal.prototype); //Clonando o objeto

Dog.prototype.speak = function(){
  return "Woof! Woof!";
}


var myDog = new Dog("Totó");
console.log("My dog "+myDog.getName()+" has learned a new trick: "+myDog.speak());

ES6 Style

class Animal {
  constructor(name) {
    this.name = name;
  }
  getName() {
    return this.name;
  }
}

class Dog extends Animal {
  constructor(name) {
    super(name);
  }
  speak() {
    return "woof";
  }
}

var dog = new Dog("Scamp");
console.log(dog.getName() + ' says ' + dog.speak());

Credits: http://jurberg.github.io/blog/2014/07/12/javascript-prototype/